Cell regulation encompasses all the functions cells carry out to maintain homeostasis, in particular their responses to extracellular signals (hormones, neurotransmitters, etc.) and how cells transduce intracellular responses prompted by such signals. In addition to endogenous agents, many drugs and environmental agents use these same mechanisms to produce their most important effects. Understanding of cell signaling processes is fundamental to all areas of cardiovascular research. Numerous research opportunities exist within this program ranging from studies exploring new cell signaling mechanisms, to those examining aberrant signaling mechanisms associated with cardiovascular disease. Significantly, many of the recent breakthroughs in cardiovascular therapeutics result from basic studies on signaling molecules.